We present a high spatial resolution multi-wavelength survey of 44 young binary star systems in Taurus-Auriga with separations of 10 1000 AU. These observations, which were obtained using the Hubble Space Telescope and the NASA Infrared Telescope Facility, quadruple the number of close (< 100 AU) binary stars with spatially resolved measurements from 0.3 to 2.2 μm and are the first 3.6 μmmeasur...

We present the results of a systematic search for Xray flares on young stars observed during ROSAT PSPC observations of the Taurus-Auriga-Perseus sky region. All pointed PSPC observations currently available from the ROSAT Public Data Archive with known pre-main sequence T Tauri Stars or young Pleiads or Hyads in the field of view are analyzed. A study of the activity of late-type stars of diff...

We present the results of a systematic search for Xray flares on young stars observed during ROSAT PSPC observations of the Taurus-Auriga-Perseus sky region. All pointed PSPC observations currently available from the ROSAT Public Data Archive with known pre-main sequence T Tauri Stars or young Pleiads or Hyads in the field of view are analyzed. A study of the activity of late-type stars of diff...

We model the process of dust coagulation in protoplanetary disks and calculate how it affects their observational appearance. Our model involves the detailed solution of the coagulation equation at every location in the disk. At regular time intervals we feed the resulting 3D dust distribution functions into a continuum radiative transfer code to obtain spectral energy distributions. We find th...

We present high resolution optical spectra obtained with the HIRES spectrograph on the W. M. Keck I telescope of seven low mass T Tauri stars and brown dwarfs (LMTTs) in Taurus-Auriga. The observed Li I 6708 Å absorption, low surface gravity signatures, and radial velocities confirm that all are members of the Taurus star forming region; no new spectroscopic binaries are identified. Four of the...

We have detected the T Tauri star, DO Tauri, in a 0.6 ′′-resolution VLA map of 43.3 GHz (λ = 7 mm) continuum emission. The 43 GHz flux density lies on the same power-law slope defined by 89 to 232 GHz measurements, F ν ∝ ν α with index α = 2.39±0.23, confirming that the 43.3 GHz emission is thermal radiation from circumstellar dust. Upper limits to the flux densities at 8.4 and 22.5 GHz constra...